Towed agricultural machines, for example, harvesting machines, such as balers, or planting or sowing machines, soil cultivation machines, agricultural sprayers, or also attachments and wagons for transporting agricultural products are known. It is further known to equip such machines with a tandem arrangement for a two-wheel tire set on both sides of a machine frame, wherein each set of two wheels is supported on a swivel-mounted tandem axle carrier that is oscillatingly suspended on a supporting axle connected to the machine frame. The machine frame is here usually structurally designed on such a tandem arrangement and provides corresponding strength and deformation stability that is usually higher due to higher bearing loads than for a machine with a single-wheel arrangement on which, on both sides of the machine frame, only one wheel is arranged on a single-wheel supporting axle. Manufacturers of agricultural towed machines offer either machines with a tandem arrangement and a machine frame designed accordingly for a tandem arrangement, or machines with a single-wheel arrangement and a machine frame designed accordingly for a single-wheel arrangement. A machine frame that is suitable for both arrangements is therefore uneconomical in production because a machine frame that is suitable for a tandem arrangement is over-dimensioned for a single-wheel arrangement, and a machine frame that is suitable for a single-wheel arrangement would be under-dimensioned for a tandem arrangement. This usually has the result that manufacturers decide on one of the arrangements for a machine type or for a machine series in order to be able to ultimately have favorable manufacturing with little part venation. Often, however, in use on the field, a machine for high bearing loads with a tandem arrangement is not absolutely necessary or a machine for lower bearing loads with a single-wheel arrangement is not sufficient. It is also a concern of the operator of agricultural machines to reduce the soil contact pressure or the rolling resistance of the towed machine depending on the weather and/or soil conditions, wherein a tandem arrangement generates a lower soil contact pressure relative to a single-wheel arrangement, but a single-wheel suspension has a lower rolling resistance relative to a tandem arrangement. To be able to provide the option of a tandem arrangement or a single-wheel arrangement for use on the field, the operator therefore must purchase two machines, which is usually associated with higher costs. If there is doubt, he might also be forced to switch the supplier or the manufacturer, which can have disadvantageous financial or also qualitative disadvantages for the operator.